During an isothermal expansion, a confined ideal gas does `-150 J` of work aginst its surroundings. This implies that

Options

A. `300J` of heat has been added to the gas
B. no heat is transferred because the process is isothermal
C. `150J` of heat has been added to the gas
D. `150J` of heat has been removed from the gas

Answer

C

Explanation

From the first law of thermodynamics
`DeltaU=Q-W`
For isothermal process , `DeltaU=0`
`:. Q = -W`
Given `W =-150J`
`:. Q = _150J`
When `Q` is positive , the heat is added to the gas.